Dynamo-electric machine.



B. G.- LAMMB.

DYNAMO ELECTRIC MACHINE APPLICATION FILED AUG. 2, '1900. RENEWED JULY3,1908.

Patented Feb. 23, 1909.

2 SHEETSSHEBT 1.

INVENTOR i857 Q M L W'LVL WlTNESSES:

ATTORNEY B. G. LAMME.

DYNAMO ELECTRIC MAGHINB.

APPLIGATION FILED AUG. 2, 190a. RENEWED JULY s, 1908.

2 SHEETSSHBET 2 INVENTOR Patented Feb. 23, 1909.

WITNESSES:

UNITED $TATES ATENT BENJAMIN G. LALlllE, OF PITTSBURG, PEKXS YLVANlA,Afr'Sl. NOR TO WESTINGHOUSE lilLilC- TRIO & MANUFACTURING COMPAN Y, AtTOl{P(Jl.t.-\JION OF PENNSYLVANIA.

DYNAMIC-E LE CTRIC IMAGE- ENE T he object of my invention is to avoidthe losses incident to the magnetization of the stationary supportingframes for the mag netizable cores of ring Wound armatures by providingmeans for preventing such magnetization. I

Alternating current generators which are adapted to be driven by steamturbines or other high speed driving engines generally comprise rotatingfield members having av small number of poles, usually two or four, andstationary ings of which are of the drum type and are located insuitable slots near the inner cylindrical core surfaces. The coils ofthese windings, by reason of the small number of poles, necessarilycomprise lon end-eonnecting portions, the two parts of a single coilbeing to 'ated in slots which are usually widely separated and, inbipolar machines, are substantially opposite each other. lVhen a machineof this type is completely wound,

the portions of the coils not located in the. slots at",- necessarilyoverlapped by a large "propin-tion of the total number of coils so thatit is a very arduous and expensive task, involving considerable lengthof time, to repair a single inside coil, in case its insulalion. ispunctured or other defects develop. Furthermore, on account of thelength and weight of the end connections and also the tendency for thecoils to become distorted when thewinding becomes short-oircuited, orwhen severe clectro-magnetic strains are imposed by external shortcircuits or for other reasons, it is necessary to provide adequatesupports for the-c portions of the winding. Diliiculty providingsuitable ventilation for the end connections of stationary drum-woundarma tures since they are massed in order to reduce to a minimum thelarge amount of armature members, the wind is also experienced inSpecification of Letters Patent. Application filed August 2. 1906,Serial No. 328,867. Renewed July 3,

Patented Feb. 23, 1909.

1903. Serial No. 441,876.

space necessarily occupied by this portion of the winding. These'difiiculties are largely overcome by the use of a stationary ring-woundarmature and, in a machine of this type, the supported frame for thelaminated armature core may preferably be made of materially largerdiameter than the core which it supports and spacing beams ofnon-magnetizable material may be interposed at frequent intervalsbetween the core and the frame. In this way, a sufficient space is leftfor the outer half of the armature convolutions but, when the machine isin. operation, a relatively strong magnetic field is set up around theoutside of the magnetizable core which tends to inagnetize thestationary supporting frame and thus produce consideral'ile heat andconsequent reduction of eiiiciency.

According to my present invention, 1 pro vide a shortcircuited secondarywinding which is of relatively low resistance, and is located bet weenthe core of the ring; winding and the stationary supporting frame forthe core structure. This secondary winding;- may be of any suitabletype, but will prefer-- ably have a form similar to that of asquirrel-cage induction motor winding.

In the accompanying drawings, Figure l is an end elevation of a portionof a stationary armature provided with the wind ing of my invention, aportion of the frame being brokeinaway to disclose the spacingconstructioi'i, and Fig. 2 is a sectional elevavtion on line ll--Il ofFig. 1.

Referring to the drawings, a cylindrical core member 1 is supported in afrantic by means of a plurality of spacing beams 23 which may preferablybe constructed of non-magiietizable material. The beams are preferablylocated in radial lancs, equally disposed about the outer cylinrlricalsurface of the core member 1, and are bolted to the frame stiaurture.

The core men'iber l. is cmistruetcd of magi'ictizable laminae which maybe held in place by any convenient means, such as dovetail projections5, which engage complen'ientary longitudinal grooves or recesses 6 inthe inner surfaces of the beams 3 and is provided with suitable slots .land ventilating ducts 4: in the usual manner. Flanged cross pieces 7 areprovided at the ends and at intermediate points of the beams 3to saidslots.

In the ring winding illustrated in the drawings,'which comprises coils 9the con ductors from any one of the slots 4L extend away from thecenter, in a radial line,

through one set of openings 9, which lie in approximately the sameradial plane as the slot, along a substantially radial line toward thecenter and into the core slot next adjacent to the one from whichtheopposite end of the coil projects.

Between the outer edges of the segment-a1 plates 8 and the frame 2, aplurality of bars 10 of conducting material are located. The ends ofthese bars are connected by shortcircuiting rings 11 and 12 whichcomplete a .short-circuited secondary winding of the, squirrel-cagetype. The location of a secondary winding in this manner tends to opposethe magnetization in the stationary supporting frame 2 which is producedby the ring wound armature winding of the machine.

Each of the bars 10 is composed of a plurality of strips of relativelythin conducting material, which are .slightly separated, and each of therings 11 and 12 is also com osed of a plurality of spaced strips in orcer to provide for suitable ventilation.

It. may be found desirable to make the conductors 10 project for somedistance at each end of the core member so that they may be bent toconform to the end curvature of the ring winding for a short distance,and.

I therefore desire that my invention shall not be restricted inthisparticular or any.

other to the exact arrangement illustrated and described.

I claim as my invention:

1. A stationary ring-wound armature for dynamo-electric machines havinga shortcircuited secondary winding outside of the ring winding.

2. In a dynamo-electric machine, the combination with a stationary ringwinding, of a secondary winding outside of the ring winding thatcomprises a plurality of longitudinally disposed conductors, andshortcircuiting end rings therefor.

3. In a dynamo-electric machine, the combination with a stationarycylindrical core member, and a ring winding therefor, of a secondarywinding outside of the ring Winding that comprises low resistanceconductors substantially parallel to the axis of the core and disposedat equal intervals around the periphery of the core and connecting ringsat each end.

'71:. Ina dynamo-electric machine, the combination with a hollowcylindrical stationary core member, a supporting frame and a ringarmature winding therefor, of a short circuited secondary windingdisposed between the ring winding and the supporting frame.

5. In a dynamo-electric machine, the combination with a hollowcylindrical stationary core member, a stationary frame and ring armaturetherefor, of means for preventing the magnetization of the supportingframe when the ringwinding is energized.

6. In a dynamo-electric machine, a magnetizable core member, asupporting frame, and a ring winding therefor, of means for preventingmagnetization of the supporting frame.

7. A stationary ring-wound armature for dynamo-electric machines havingnon-magnetizable supports for the windin and a short-circuited secondarywinding outside of said ring winding.

8. In a dynamo-electric machine, the combination" with a stationaryring-wound armature, a supporting frame therefor of materially greaterdiameter than the armature, a spacing and coil-supporting structureinterposed between the stationary frame and the armature, and ashort-circuited second ary winding located between the ring winding andthe supporting frame.

9. In a dynamo-electric machine, the combination with a stationaryring-woundarmature, a supporting frame therefor of materially greaterdiameter than the armature,

a spacing and coil-supporting structure interposed between thestationary frame and the armature, and a short-circuited secondarywinding located between the ring winding and the supporting frame thatcomprises a plurality of iongitudinally disposed low resistanceconductors and short-circuiting end rings therefor.

10. In a dynamoelectric machine, the combination with a hollow,cylindrical core member, a stationary frame which surrounds said membervand is of materially greater diameter, a spacing structure ofnon-magnetizable material which is interposed between the stationaryframe and the core member and comprises beams suitably disposed aboutthe circumference of the core member in m1 dialplanes, segmentalcoil-supporting plates which interconnect said beams, and ashortcircuited secondary winding located between the ring winding andthe supporting frame. 7

dial planes, segmental coil-supportingplates Which interconnect saidbeams, and a short- In testimony whereof, I have hereunto.

subscribed my name this 28th day of July circuited secondary windinglocated between 1906.

the ring winding and the supporting frame that comprises a plurality oflongitudinally disposed low resistance conductors and short oil-(suitingend rings therefor.

BENJ. G. LAMME. \Vitnesses:

OTTO S. Si'inuuuk. B'mNnY Hives.

